Discovery of a potent, orally available, and isoform-selective retinoic acid β2 receptor agonist
4′-Octyl-4-biphenylcarboxylic acid (1g, AC-55649) was identified as a highly isoform-selective agonist at the human RARβ2 receptor in a functional intact cell-based screening assay. The subsequent hit to lead optimization transformed the lipophilic, poorly soluble hit into a more potent and orally available compound (2, AC-261066) with retained β2 selectivity and greatly improved physiochemical pr